Making and Riding the Un-Cycle (Back Pedaler)

Contents

Idea of Back Pedaler

A double wheel unicycle is a unicycle wheel stack where one wheel
drives the other backwards. I originally learned to ride, idle
one footed, and juggle on it but what I could not do was pedal
forwards (ie. ride backwards). Another problem I had with the
double wheel was that after numerous drops it fatigues the joints
and it eventually breaks. Also I like to stop short on it and
the tires would sometimes slip (high pressure between the tires
is also not good as it makes the wheels hard to turn). I figured
a gear on both sides would get the unicycle at a reasonable height
where I can be brave enough to learn to ride backwards (ie. pedal
forwards) and it also survive numerous drops since it would not
come down from a height. I sent this idea to Tom Miller of the
Unicycle Factory. Tom Miller did the hard part turning the idea
into reality. I received it in mid February 2012.

Pieces of Back Pedaler

Back Pedaler screws hold two gear boxes together from underneath.

Custom flange, 18 spoke holes, 9 decorative, and one for axle.
Grooves in flange to accept gear and locking screw.

Back Pedaler gear box. A collection of brass spacers
is provided to get the 2 gears to mesh exactly right...
not too tight and not too loose. 6 bearings are needed to hold
the 4 gears and 3 axles.

Back Pedaler axle with flange and gears assembled. Notice the holes on top of boxes, they are used to screw the top gears in place and also to inject grease into the assembly.

Back pedaler spoked wheel (4 cross) with gears.

Whole Back Pedaler as shipped (Un-Cycle). Powder coated frame.

Close up of Back Pedaler.

How to take apart Back Pedaler. (In purple, one dot gear box for
.008 and .010 spacer, two dot gear box has .015 spacer. This fine
tuning spaces the gears apart, just right.)

I have "rough" design specs. I am not sure how to present yet.
Let me know if interested.

Experiences Riding

I can now go backwards. :) It took me a while. I found one
foot idle harder than double wheel, as a giraffe idles slower.
Also got a circus idle down (almost a still stand with pedals at
same level)... for a double wheel that would be harder,
as it tends to slip.

I am now learning how to juggle confidently. I also found going
backwards between pylons a little too hard yet.

Its still so much fun... and still a little scary too.
By far, my favorite unicycle.